Definition: In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
Input: ['l', 'z', 'u', '9557', '4991', '9675', 'd', '8229', '469', '2229']

d, l, u, z